An approach is provided for dynamic obstacle data in a collision probability map. The approach, for example, involves monitoring a flight of an aerial vehicle through a three-dimensional (3D) space that is partitioned into 3D shapes of varying resolutions. The approach also involves detecting an entry of the aerial vehicle into one 3D shape of the plurality of 3D shapes. The approach further involves, on detecting an exit of the aerial vehicle form the one 3D shape, recording a 3D shape identifier (ID) of the one 3D shape and at least one of a first timestamp indicating the entry, a second timestamp indicating the exit, a duration of stay in the one 3D shape, dimensions of the aerial vehicle, or a combination thereof as a dynamic obstacle observation record. The approach further involves transmitting the dynamic obstacle observation record to another device (e.g., a server for creating the collision probability map).